The internal female genitalia of Aulacigaster (Diptera: Aulacigastridae)-description and phylogenetic analysis

摘要

The internal female genitalia of 22 species of Aulacigaster are studied, covering all species groups as defined by Rung and Mathis (Smithson. Contrib. Zool., 633, 1-132, 2011). The method of embedding freshly dissected material in polyvinyl lactophenol with an admixture of chlorazol black E is far superior to results achieved by maceration in potassium hydroxide and allows the detection of delicate structures previously unnoticed. A general description of the internal female genitalia introduces all relevant structures and their variation within the genus. Establishing the presence and the multi-chambered condition of the ventral receptacle in Aulacigastridae constitutes a major result. Another important finding pertains to the presence of a ventral sclerotized ring in the posteroventral wall of the vagina, which had not been described in Aulacigastridae before. The variable characters are coded across the studied species and are subjected to a phylogenetic analysis in combination with the character set of Rung and Mathis (Smithson. Contrib. Zool., 633, 1-132, 2011). The resulting topology is used to reconstruct ancestral character states and to discuss intrafamilial character state changes at and above the species group level. Information extracted from the internal female genitalia corroborates and adds resolution to the results of previous analyses that employed characters of the external morphology and the male terminalia. Brief per species descriptions and additional illustrations are placed in the electronic supplementary material.